AWS Cognito - How To Get User's Group From Token Object

Question

I can see the user's assigned User Pool group in the returned user data object in the console after logging in. Everything I've tried to assign the group to a variable has failed. What am I missing? I can easily get the client_id, JWT's, and attributes.

The object path:

let userGroup = user.signInUserSession.accessToken.payload.cognito.groups[0];

However, this works:

user.signInUserSession.accessToken.payload.client_id;

This section of the object looks like this. I can retrieve the token, the user name, almost anything but groups.

signInUserSession: CognitoUserSession
    accessToken: CognitoAccessToken
        jwtToken: ...
        payload:
            auth_time: 1539824552
            client_id: "5u7o1o1...."
            cognito:groups: Array(1)
                0: "admin-full"
                length: 1
        ... more properties here...
        token_use: "access"
        username: "me"

I'm using Angular 6 and AWS-Amplify but I doubt that matters. Part of my code:

constructor(
    private amplifyService: AmplifyService,
  ) {}

this.amplifyService.auth().currentAuthenticatedUser()
      .then(user => {
         console.log('user data in checkLogin: ', user); // The whole object.
         console.log('user token in checkLogin: ', user.signInUserSession.accessToken.jwtToken); // Retrieves the token.

My whole session object for clarification:

CognitoUser {username: "me", pool: CognitoUserPool, Session: null, client: Client, signInUserSession: CognitoUserSession, …}
Session: null
attributes: {phone_number: "########", locale: "Silicon Valley", given_name: "J", family_name: "Preston", email: "[email protected]"}
authenticationFlowType: "USER_SRP_AUTH"
client: Client {endpoint: "https://cognito-idp.us-west-2.amazonaws.com/", userAgent: "aws-amplify/0.1.x js"}
pool: CognitoUserPool {userPoolId: "us-west-2_UW9KsJm0o", clientId: "5u7o1o1v288e...", client: Client, advancedSecurityDataCollectionFlag: true, storage: Storage}
preferredMFA: "NOMFA"
signInUserSession: CognitoUserSession
accessToken: CognitoAccessToken
jwtToken: "eyJraWQiOiJwaUdRSnc..."
payload:
auth_time: 1539881072
client_id: "5u7o1o1v2..."
cognito:groups: ["admin"]
event_id: "168d9cc3-d2f5-11e8-ae71-f734087f965a"
exp: 1539884672
iat: 1539881072
iss: "https://cognito-idp.us-west-2.amazonaws.com/us-west-2_UW9KsJm0o"
jti: "13c4c552-ee70-4f8a-b64d-f95e0bdc81cf"
scope: "aws.cognito.signin.user.admin openid"
sub: "96a047b2-ae9a-42ff-af09-fc1c0802b88f"
token_use: "access"
username: "me"
version: 2
__proto__: Object
__proto__: CognitoJwtToken
clockDrift: 0
idToken: CognitoIdToken {jwtToken: "eyJraWQiOiI...", payload: {…}}
refreshToken: CognitoRefreshToken {token: ""}
__proto__: Object
storage: Storage {CognitoIdentityServiceProvider.5u7o1o1....LastAuthUser: "me", CognitoIdentityServiceProvider.5u7o1o1v....jimadmin.accessToken: "eyJraWQiOiJ...", CognitoIdentityServiceProvider.5u7o1o1....jimadmin.idToken: "eyJraWQiOiI3...", CognitoIdentityServiceProvider.5u7o1o1....jimadmin.refreshToken: "", CognitoIdentityServiceProvider.5u7o1o1....jimadmin.tokenScopesString: "email openid aws.cognito.signin.user.admin", …}
username: "me"

Answer 1

The group is in the session Object and in the idToken Payload as seen below.
The group is not there if your user is not in a group. You should be able to access it like accessToken.payload['cognito:groups'];

I happen to have a cognito session object handy for a user in a group, which shows all tokens and all their payloads. As well as what you get when you get the user attributes.

session:

{
   "idToken":{
      "jwtToken":"eyJraWQiOiJQS1wvMHNNMlk...",
      "payload":{
         "sub":"ceb234234-b0e0-4c3d-8abc-af08c002b4de",
         "cognito:groups":[
            "user"
         ],
         "email_verified":true,
         "iss":"https://cognito-idp.us-east-2.amazonaws.com/us-east-2_sinJIhGA8",
         "phone_number_verified":false,
         "cognito:username":"ceba8336-b0e0-4c3d-8abc-af08c002b4de",
         "aud":"203e1rl2o1d8d5chhs9v6s1i79",
         "event_id":"89502ffe-d2fe-11e8-8427-1b3482253d90",
         "token_use":"id",
         "auth_time":1539885130,
         "exp":1539888730,
         "iat":1539885130,
         "email":"[email protected]"
      }
   },
   "refreshToken":{
      "token":"eyJjdHkiOiJKV1QiLCJlb..."
   },
   "accessToken":{
      "jwtToken":"eyJraWQiOiI4N2pRRnpqSm..",
      "payload":{
         "sub":"ceba8336-b0e0-4c3d-8abc-af08c002b4de",
         "device_key":"us-east-2_94234234234b-4cec-ae49-b1f90555d979",
         "cognito:groups":[
            "user"
         ],
         "iss":"https://cognito-idp.us-east-2.amazonaws.com/us-east-2_sinJIhGA8",
         "client_id":"203e1rl223423hhs9v6s1i79",
         "event_id":"895234fe-d2fe-11e8-8427-1b3482253d90",
         "token_use":"access",
         "scope":"aws.cognito.signin.user.admin",
         "auth_time":1539885130,
         "exp":1539888730,
         "iat":1539885130,
         "jti":"936fd8f9-c091-4f642345f-ba9454f16b9c",
         "username":"ceba83362342-4c3d-8abc-af08c002b4de"
      }
   },
   "clockDrift":0
}

userAttributes:

{  
   "details":[  
      {  
         "Name":"sub",
         "Value":"ceba8336-4234-4c3d-8abc-af08c002b4de"
      },
      {  
         "Name":"email_verified",
         "Value":"true"
      },
      {  
         "Name":"phone_number_verified",
         "Value":"false"
      },
      {  
         "Name":"email",
         "Value":"[email protected]"
      }
   ]
}